It is already known from Applicant's own prior publication to provide an interconnection network for the core of an integrated services digital type network whereby the specialized modular units constituting the core are interconnected point-to-point, as a function of their communication requirements.
Such a network is designed to incorporate a sub-network relating to units that support packet mode, i.e. units within the core that are directly or indirectly involved whenever packet form data is switched. Conventionally, such data packets are switched by switches having a centralized structure in a bus or loop distributed network, each switch including a memory in which incoming packets are temporarily stored until the moment they are forwarded to destinations that depend on address information contained in their respective headers.